Power over Ethernet (PoE) provides network connectivity with both power and data transmission to remote devices. PoE is employed to power telephones, wireless local area networks access points, network cameras, remote network switches, embedded appliances, and other devices. PoE can be implemented according to IEEE 802.3-2005 Standard (referred to as IEEE802.3af). This Standard specifies powering devices at a voltage of between 36-57 V DC over Cat. 3/Cat. 5e cables with a selectable current of between 10-400 mA subject to a maximum power load of 15.4 Watts. In practice, only about 12.95 Watts of power is typically available out of PoE due to power losses in the cables.
A PoE switch includes one or more ports to which an external device is connected. Each port includes a pair of light emitting diodes (LEDs). A link LED typically emits green light to indicate that a power link is established with the external device and amber light to indicate identification of a fault in product code. A mode LED is typically configured to emit a single color of light to indicate traffic of data through the port.
Users of PoE switches desire improved function and performance, especially as PoE implementation expands.